Until now, when such protective angle strips have been provided, they have been handled essentially manually. Once put into place on the vertical edges of the load they are held there by binding or by some other similar means. That technology suffers not only from the drawback inherent to all manual handling (cost, low throughput, or the like), but any mechanization runs into a problem of interference with the moving members used for and during packaging. Such problems have had the effect of limiting the use of such angle strips, even though they present many advantages for palletized loads contained in outer packaging that applies large compression forces. A mechanization technique has been proposed (see Document EP-A-0 060 543), but it applies essentially to the top horizontal edges and not to vertical edges. In addition, that technique considerably slows down throughput. Reference may also be made to the following documents: DE-A-2 431 153, U.S. Pat. No. 4,587,791, FR-A-2 540 828, and U.S. Pat. No. 4,671,046.
The state of the art concerning known methods and machines for applying outer packaging to palletized loads includes the following documents in particular: FR-A-2 468 506, FR-A-2 470 056, U.S. Pat. No. 4,587,796, FR-A-2 228 669, FR-A-2 243 113, FR-A-2 413 270, FR-A-2 281 275, U.S. Pat. No. 4,473,990, EP-A-0 184 485, EP-A-0 177 413, EP-A-0 180 517, and U.S. Pat. No. 4,587,796. In general, those methods and machines are well known to the person skilled in the art, and the techniques implemented may be the following: the "curtain" technique, straight or helical winding over the full width or using bands, or applying a tube covering. In the "curtain" technique, a curtain of outer packaging film is set up between two vertical axis film reels; then the load is caused to advance horizontally towards the curtain of film which is deformed into a U-shape; after which the curtain is closed and fastened together. In the winding technique, relative pivoting is established about a vertical axis between the load and a reel of film in strip form. This winding technique includes several different variants: the load may remain stationary and the reel of film may be rotated around the load (a stationary load and rotating reel machine); the load may be rotated, with the axis of the reel of film in strip form remaining in a fixed position (a turntable machine). The width of the strip of film may be the same as the height of the load or it may be a fraction thereof. The winding may be straight or helical. The winding technique is also applicable to a load that extends horizontally and that is subjected to relative displacement along its axis. The reel of film in strip form then has a horizontal axis. In the technique using a tube covering, a flattened tube of film is wound onto a reel. The tube is withdrawn from the reel and is opened and stretched so as to be fitted over the load by sliding vertically downwards, using means such as fingers, clamps, a supporting frame, belts, chains, and the like. These techniques make use of film that may be perforated like a net, or that may be unperforated. The film is a heat-shrink film or a stretch film. If it is a stretch film it may be stretched or it may be pre-stretched. The entire load or only a portion thereof may be covered by the film. These techniques may be varied, in particular as follows: a top or bottom sheet or endplate or frame may be placed on the top or bottom horizontal face of the load (for example, between the pallet and the load). The outer packaging film may comprise a plurality of layers. The pallet may be replaced by a false pallet. An outer packaging machine may be integrated into an installation which includes a palletizing machine upstream.